NAD+ homeostasis plays role in mitochondrial biogenesis during beige adipocyte differentiation

Introduction: In addition to its roles as a vascular signaling molecule, nitric oxide (NO) plays roles in metabolism. Mice deficient in eNOS are overweight and develop insulin resistance. It is not known whether the metabolic effects are due to primary roles of NO, or to increased visceral adiposity, leading to secondary metabolic changes. Hypothesis: We hypothesized that NO plays distinct and separable primary roles in white and brown adipogenesis, which underlie the effects on adiposity, energy metabolism, and expression of thermogenic genes. Methods: We exposed wild-type and mice carrying specific gain of function and loss of function eNOS mutations to cold at 4C for 48 hours and assessed expression of thermogenic gene programs in white and brown adipose tissue. To study cell autonomous effects, we differentiated adipocyte precursors from brown and white fat in the presence of NOS inhibitors and NO donors, as well as with siRNA to knockdown eNOS expression. Results: Cold exposure resulted in upregulation of the thermogenic gene program in brown adipose tissue. Animals carrying a gain of function mutation in eNOS showed increased UCP1 expression even without cold exposure. Induction of thermogenic genes was more pronounced in the animals with gain of function eNOS mutation. Differentiation of adipocyte precursors showed effects of eNOS on adipogenesis. Cells treated with the pharmacologic blockade (L-NAME and L-NA) as well as genetic knockdown (siRNA) showed dose-dependent inhibition of adipocyte differentiation. MitoTracker Red CMXRos staining showed that treatment with the NO donor SNAP increases mitochondrial biogenesis, while L-NAME decreases mitochondrial biogenesis. Conclusions: We show that eNOS-derived NO plays distinct and separable roles in white and brown adipogenesis. In brown adipocytes, eNOS regulates the expression of the thermogenic gene program, with upregulation of expression even without cold exposure, and greater increase in response to cold. In white adipocytes, eNOS-derived NO is required for adipocyte differentiation and mitochondrial biogenesis.

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Egr1 loss-of-function promotes beige adipocyte differentiation and activation specifically in inguinal subcutaneous white adipose tissue

Scientific Reports ◽

10.1038/s41598-020-72698-w ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Marianne Bléher ◽

Berbang Meshko ◽

Isabelle Cacciapuoti ◽

Rachel Gergondey ◽

Yoann Kovacs ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Adipocyte Differentiation ◽

Uncoupling Protein ◽

Subcutaneous Fat ◽

Loss Of Function ◽

Beige Adipocyte ◽

Subcutaneous White Adipose Tissue ◽

Fat Depots ◽

Beige Adipocytes

Abstract In mice, exercise, cold exposure and fasting lead to the differentiation of inducible-brown adipocytes, called beige adipocytes, within white adipose tissue and have beneficial effects on fat burning and metabolism, through heat production. This browning process is associated with an increased expression of the key thermogenic mitochondrial uncoupling protein 1, Ucp1. Egr1 transcription factor has been described as a regulator of white and beige differentiation programs, and Egr1 depletion is associated with a spontaneous increase of subcutaneous white adipose tissue browning, in absence of external stimulation. Here, we demonstrate that Egr1 mutant mice exhibit a restrained Ucp1 expression specifically increased in subcutaneous fat, resulting in a metabolic shift to a more brown-like, oxidative metabolism, which was not observed in other fat depots. In addition, Egr1 is necessary and sufficient to promote white and alter beige adipocyte differentiation of mouse stem cells. These results suggest that modulation of Egr1 expression could represent a promising therapeutic strategy to increase energy expenditure and to restrain obesity-associated metabolic disorders.

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Aquaglyceroporins Are Differentially Expressed in Beige and White Adipocytes

International Journal of Molecular Sciences ◽

10.3390/ijms21020610 ◽

2020 ◽

Vol 21 (2) ◽

pp. 610

Author(s):

Inês Vieira da Silva ◽

Francisco Díaz-Sáez ◽

António Zorzano ◽

Anna Gumà ◽

Marta Camps ◽

...

Keyword(s):

Adipose Tissue ◽

Adipocyte Differentiation ◽

Expression Patterns ◽

Physiological Role ◽

Glycerol Metabolism ◽

Metabolic Complications ◽

Altered Expression ◽

Beige Adipocyte ◽

White Adipocyte ◽

White Adipocytes

Browning of white adipocytes has been proposed as a powerful strategy to overcome metabolic complications, since brown adipocytes are more catabolic, expending energy as a heat form. However, the biological pathways involved in the browning process are still unclear. Aquaglyceroporins are a sub-class of aquaporin water channels that also permeate glycerol and are involved in body energy homeostasis. In the adipose tissue, aquaporin-7 (AQP7) is the most representative isoform, being crucial for white adipocyte fully differentiation and glycerol metabolism. The altered expression of AQP7 is involved in the onset of obesity and metabolic disorders. Herein, we investigated if aquaglyceroporins are implicated in beige adipocyte differentiation, similar to white cells. Thus, we optimized a protocol of murine 3T3-L1 preadipocytes browning that displayed increased beige and decreased white adipose tissue features at both gene and protein levels and evaluated aquaporin expression patterns along the differentiation process together with cellular lipid content. Our results revealed that AQP7 and aquaporin-9 (AQP9) expression was downregulated throughout beige adipocyte differentiation compared to white differentiation, which may be related to the beige physiological role of heat production from oxidative metabolism, contrasting with the anabolic/catabolic lipid metabolism requiring glycerol gateways occurring in white adipose cells.

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Depletion of white adipocyte progenitors induces beige adipocyte differentiation and suppresses obesity development

Cell Death and Differentiation ◽

10.1038/cdd.2014.148 ◽

2014 ◽

Vol 22 (2) ◽

pp. 351-363 ◽

Cited By ~ 31

Author(s):

A C Daquinag ◽

C Tseng ◽

A Salameh ◽

Y Zhang ◽

F Amaya-Manzanares ◽

...

Keyword(s):

Adipocyte Differentiation ◽

Beige Adipocyte ◽

White Adipocyte ◽

Adipocyte Progenitors

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FOXP4 differentially controls cold-induced beige adipocyte differentiation and thermogenesis

10.1101/2021.10.11.463898 ◽

2021 ◽

Author(s):

Fuhua Wang ◽

Shuqin Xu ◽

Tienan Chen ◽

Shifeng Ling ◽

Wei Zhang ◽

...

Keyword(s):

Cell Fate ◽

Transcriptional Repression ◽

Adipocyte Differentiation ◽

Brown Adipocytes ◽

Beige Adipocyte ◽

Forkhead Box ◽

Beige Adipocytes ◽

Adipocyte Cell ◽

Adipocyte Development ◽

Fibroblastic Cells

Beige adipocytes possess a discrete developmental origin and notable plasticity in thermogenic capacity in response to various environmental cues. But the transcriptional machinery controlling beige adipocyte development and thermogenesis remains largely unknown. By analyzing beige adipocyte-specific knockout mice, we identified a transcription factor, Forkhead Box P4 (FOXP4) that differentially governs beige adipocyte differentiation and activation. Depletion of Foxp4 caused a decline in the frequency of beige preadipocytes by switching their cell fate towards fibroblastic cells at the expense of beige adipocytes. However, we observed that ablation of Foxp4 in differentiated adipocytes profoundly potentiated their thermogenesis upon cold exposure. Of note, the outcome of Foxp4-deficiency on UCP1-mediated thermogenesis was confined to beige adipocytes, rather than to brown adipocytes. Taken together, we submit that FOXP4 primes beige adipocyte cell fate commitment and differentiation by potent transcriptional repression of the thermogenic program.

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Egr1 loss-of-function promotes beige adipocyte differentiation and activation specifically in inguinal subcutaneous white adipose tissue

10.1101/2020.06.03.131342 ◽

2020 ◽

Author(s):

Marianne Bléher ◽

Berbang Meshko ◽

Rachel Gergondey ◽

Yoann Kovacs ◽

Delphine Duprez ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Adipocyte Differentiation ◽

Uncoupling Protein ◽

Subcutaneous Fat ◽

Loss Of Function ◽

Beige Adipocyte ◽

Subcutaneous White Adipose Tissue ◽

Fat Depots ◽

Beige Adipocytes

AbstractExercise, cold exposure and fasting lead to the differentiation of inducible-brown adipocytes, called beige adipocytes, within white adipose tissue and have beneficial effects on fat burning and metabolism, through heat production. This browning process is associated with an increased expression of the key thermogenic mitochondrial uncoupling protein 1, Ucp1. Egr1 transcription factor has been described as a regulator of white and beige differentiation programs, and Egr1 depletion is associated with a spontaneous increase of subcutaneous white adipose tissue browning, in absence of external stimulation. Here, we demonstrate that Egr1 mutant mice exhibit a restrained Ucp1 expression specifically increased in subcutaneous fat, resulting in a metabolic shift to a more brown-like, oxidative metabolism, which was not observed in other fat depots. In addition, Egr1 is necessary and sufficient to promote white and alter beige adipocyte differentiation of mouse stem cells. These results suggest that modulation of Egr1 expression could represent a promising therapeutic strategy to increase energy expenditure and to restrain obesity-associated metabolic disorders.

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Egr1 deficiency induces browning of inguinal subcutaneous white adipose tissue in mice

10.1101/150003 ◽

2017 ◽

Author(s):

Cécile Milet ◽

Marianne Bléher ◽

Kassandra Allbright ◽

Mickael Orgeur ◽

Fanny Coulpier ◽

...

Keyword(s):

Extracellular Matrix ◽

Adipose Tissue ◽

Energy Expenditure ◽

White Adipose Tissue ◽

Adipocyte Differentiation ◽

Uncoupling Protein ◽

Negative Regulator ◽

Molecular Signature ◽

Beige Adipocyte ◽

Matrix Gene

AbstractBeige adipocyte differentiation within white adipose tissue, referred to as browning, is seen as a possible mechanism for increasing energy expenditure. The molecular regulation underlying the thermogenic browning process has not been entirely elucidated. Here, we identify the zinc finger transcription factor EGR1 as a negative regulator of the beige fat program. Loss of Egr1 in mice promotes browning in the absence of external stimulation and activates Ucp1 that encodes the key thermogenic mitochondrial uncoupling protein-1. Moreover, EGR1 is recruited to the proximal region of the Ucp1 promoter in subcutaneous inguinal white adipose tissue. Transcriptomic analysis of subcutaneous inguinal white adipose tissue in the absence of Egr1 identifies the molecular signature of white adipocyte browning downstream of Egr1 deletion and highlights a concomitant increase of beige differentiation marker and decrease in extracellular matrix gene expression. Conversely, Egr1 overexpression in mesenchymal stem cells decreases beige adipocyte differentiation, while increasing extracellular matrix production. These results uncover the role of Egr1 in blocking energy expenditure via direct Ucp1 transcription regulation and highlight Egr1 as a therapeutic target for counteracting obesity.

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PAR2 Deficiency Induces Mitochondrial ROS Generation and Dysfunctions, Leading to the Inhibition of Adipocyte Differentiation

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6683033 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Yeo Jin Park ◽

Bonggi Lee ◽

Dae Hyun Kim ◽

Eun-Bin Kwon ◽

Younghoon Go ◽

...

Keyword(s):

Adipose Tissue ◽

Mitochondrial Biogenesis ◽

Adipocyte Differentiation ◽

Ros Generation ◽

Chow Diet ◽

Adipose Tissues ◽

Mitochondrial Ros ◽

Protease Activated Receptor 2 ◽

G Protein Coupled ◽

Deficient Mice

Protease-activated receptor 2 (PAR2) is a member of G-protein-coupled receptors and affects ligand-modulated calcium signaling. Although PAR2 signaling promotes obesity and adipose tissue inflammation in high fat- (HF-) fed conditions, its role in adipocyte differentiation under nonobesogenic conditions needs to be elucidated. Here, we used several tissues and primary-cultured adipocytes of mice lacking PAR2 to study its role in the development of adipose tissues. C57BL/6J mice with PAR2 deficiency exhibited a mild lipodystrophy-like phenotype in a chow diet-fed condition. When adipocyte differentiation was examined using primary-cultured preadipocytes, PAR2 deficiency led to a notable decrease in adipocyte differentiation and related protein expression, and PAR2 agonist treatment elevated adipocyte differentiation. Regarding the mechanism, PAR2-deficient preadipocytes exhibited impaired mitochondrial energy consumption. Further studies indicated that calcium-related signaling pathways for mitochondrial biogenesis are disrupted in the adipose tissues of PAR2-deficient mice and PAR2-deficient preadipocytes. Also, a PAR2 antagonist elevated mitochondrial reactive oxygen species and reduced the MitoTracker fluorescent signal in preadipocytes. Our studies revealed that PAR2 is important for the development of adipose tissue under basal conditions through the regulation of mitochondrial biogenesis and adipocyte differentiation.

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A Method to Induce Brown/Beige Adipocyte Differentiation from Murine Preadipocytes

BIO-PROTOCOL ◽

10.21769/bioprotoc.4265 ◽

2021 ◽

Vol 11 (24) ◽

Author(s):

Andréa Rocha ◽

Beatriz Guerra ◽

Jeremie Boucher ◽

Marcelo Mori

Keyword(s):

Adipocyte Differentiation ◽

Beige Adipocyte ◽

Murine Preadipocytes

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